The Oscar-winning 'Dallas Buyers Club' star reportedly told a group of teenagers to ''back off'' after they began poking the animal with a stick while he was surfing on the beach in Malibu, California.

A source told the National Enquirer: ''Matthew told the kids the seal wasn't hurt, it was resting and sunning itself - and that young pups do this all the time while the mother seal's swim close by until they are ready to re-enter the sea.

''After a 20-minute lecture on sea life, the kids were so anxious to get away that they didn't even bother to ask the star to pose for a photo.''

This comes after Matthew's mother Kay McCabe praised her son for his kind-hearted nature last month.

She told People magazine: ''Matthew makes me proud because he is very humble and sincere and a very thoughtful person. He is just a great son.''